A Low Current Mismatch Charge Pump for Phase-Locked Loop

A low current mismatch charge pump is proposed in 65nm CMOS process. By adopting the discharging current compensation circuit and the charging current compensation circuit, these performances, which include output voltage matching range and current mismatch, are effectively improved. Simulation results show that the proposed charge pump achieves the matching range of 0.12V~1.02V with 1.2V power supply voltage. When output voltage V
ctrl
is changed from 0.12V to 1.02V, the current mismatch of charging current and discharging current is less than 0.5%. When output voltage V
ctrl
is changed from 0.2V to 1.0V, the current mismatch of charging current and discharging current is less than 0.05%.